Following the transaction, APG will hold an approximate 64% majority stake in the German North Sea wind farm, while Trig will own a 36% equity interest.
The 66-turbine project is currently owned by investment firms Partners Group (50%) and InfraRed Capital Partners (25%), marine engineers Deme Concessions (12.5%), GE Financial Services (6.25%) and the French environment and management agency (Ademe) (6.25%).
Trig said it plans to sell a share to minority co-investors managed by InfraRed shortly after, or at, completion of the transaction, which is expected in the first half of 2020, leaving it with about a 25% stake.
Merkur consists of 66 GE Haliade 150-6MW turbines and was fully commissioned in June 2019.
It receives a guaranteed revenue under a feed-in tariff due to last until June 2033, followed by a floor price for a further six years.